In Genesis, what was the Ark’s roof designed to have around its top?

In Genesis, the Ark’s roof was designed with an opening one cubit high around its top.

Genesis 6:16 describes the Ark’s arrangement and tells Noah to finish it to a cubit above. Many English translations understand this as an opening or window-like feature near the top of the vessel, associated with ventilation and light. The verse also mentions a door in the side and three levels.

The exact Hebrew wording and the architectural interpretation have been debated. Some translations render the feature as a roof, skylight, or opening rather than describing a modern window. That uncertainty is why the answer is best stated using the traditional measurement and the general idea of an opening.

This detail is separate from the Ark’s entrance, which Genesis places in its side. It also should not be confused with a deck count: the Ark is described as having three levels.